The gown was first worn during the Middle Ages when scholars were also clerics and therefore wore robes that were modeled from monks. The official term of this academic dress was known as vestimentuk clausum. The true "academic dress" was not formalized until the 14th century, when the specific cut and shape of the gown was important.
Hoods were originally a part of everyday dress, as a hood was traditional clerical headdress and was used to protect the head from inclement weather. The first official usage of this hood was by the Council of Oxford Stephen Langton. In 1222, the Archbishop of Canterbury ordered that all clerks would wear this hood as part of the academic dress. Eventually this became worn less and less by the clergy and became strictly known as academic costume in 1450.
The original use of color for gowns and hoods was not based on any exact colors. Some tendencies were seen early on as white was used for the faculty of theology, yellow and green for the faculty of medicine and blue for the faculty of philosophy. Eventually an intercollegiate commission was formed in the United States in 1893, which prepared a code that set the color used for gowns, caps and hoods that show the type of degree as well as the source of the degree.
Caps were originally used to keep the head warm as scholars would study in drafty buildings. The mortar board cap has been traced back to the 15th century. The tassel is thought to originate from when professors would decorate the cap with a string of pearls, feathers or embroidery. This is the symbol of attaining the title of "doctor," as the mortar board cap was presented to graduates upon graduation as far back as medieval times. Once the cap was received, the individual had the authority to teach others.